Microemulsion-based delivery of triamcinolone acetonide to posterior segment of eye using chitosan and butter oil as permeation enhancer: an in vitro and in vivo investigation

The aim of the study was to formulate a microemulsion (ME) using chitosan (CH) and the butter oil (BO) as a permeation enhancer for targeting drug to the posterior segment of the eye, via topical route. Triamcinolone acetonide (TA) was selected as the model drug since it undergoes extensive first-pass metabolism, leading to poor oral bioavailability of 23%. For optimisation of BO concentration, different ratios of TA:BO were prepared by simple physical mixing in the ratio of 1:9 to 9:1 and diffusion study was performed. MEs containing TA, TA:BO and TA CH ME were formulated by water titration method. Globule sizes of TA ME, TA:BO ME and TA CH ME were found to be 66.06?±?0.32?nm, 78.52?±?1.50?nm and 97.30?±?2.50?nm, respectively. In ex vivo diffusion studies using goats eye, TA:BO ME (31.33?±?0.46 and 33.98?±?0.23) and TA CH ME (24.10?±?0.41 and 27.00?±?0.18) showed higher percentage of drug diffusion in comparison to TA ME (13.29?±?0.41and 15.56?±?0.34) and TA solution (8.20?±?1.04 and 10.39?±?0.22) in presence and in absence of vitreous humour. Fluorescence intensity of coumarin-6 (as a marker) loaded ME with BO and CH was found to be higher, confirming their role in altering membrane permeability and facilitating coumarin-6 diffusion to the posterior chamber. Overall, it was concluded that BO enhances the bioavailability of TA across the retina, thereby proving its potential as permeation enhancer in facilitating drug delivery to the posterior segment of the eye.     

D-Optimal Design in the Development of Rheologically Improved In Situ Forming Ophthalmic Gel

In situ forming ophthalmic gels need to be fine tuned considering all the biopharmaceutical challenges of the front of the eye in order to increase drug residence time at the application site resulting in its improved bioavailability and efficacy. The aim of this study was to develop in situ forming ophthalmic poloxamer P407/poloxamer P188/chitosan gel fine tuned in terms of polymer content, temperature of gelation, and viscosity. Minimizing the total polymer content while retaining the advantageous rheological properties has been achieved by means of D-optimal statistical design. The optimal in situ forming gel was selected based on minimal polymer content (P407, P188, and chitosan concentration of 14.2%, 1.7%, and 0.25% w/w, respectively), favorable rheological characteristics, and in vitro resistance to tear dilution. The optimal in situ forming gel was proved to be robust against entrapment of active pharmaceutical ingredients making it a suitable platform for ophthalmic delivery of active pharmaceutical ingredients with diverse physicochemical properties.     

生物相关性溶出度方法研究进展

摘要：建立具有生物相关性的溶出度方法目的在于通过理想的体外溶出试验预测体内药代动力学过程。近年来,研究表明在生物相关性溶出介质中选择合适的溶出装置进行溶出试验得到的溶出曲线能较好地反映其在体内的溶出行为,计算机模拟软件可为建立合理的体外溶出度方法提供指导和依据。通过采用合适的生物相关性溶出介质、溶出装置,结合计算机模拟软件可建立A级水平的IVIVC(in vitro-in vivo correlation),可能代替生物等效性研究。     

注射用糜蛋白酶中组胺类物质检查方法学研究

【摘要】目的：建立注射用糜蛋白酶中组胺类物质检查方法。 方法：采用组胺检查法对注射用糜蛋白酶中组胺类物质进行限度检查方法学研究,并与现行猫法进行比较研究。结果：加标回收率86%～117%;豚鼠法方法特异性(真阴性率)100%,灵敏度(真阳性率)70%,猫法方法特异性100%,灵敏度70%;四个实验室室内重复性分别为82%、75%、83%、81%;实验室间重复性为92.9%～96.4%.结论：该方法准确与猫法相当、重复性好,可作为降压物质检查法的替代方法。